The flow behavior and the microstructural evolution of aluminum alloy 7055 in two heat treatment conditions (homogenized vs. pre-rolled, solution treated, stretched and naturally aged (T3)) were investigated for a height reduction of 60% with deformation temperatures ranging from 370 °C to 450 °C and strain rates ranging from 0.01 s−1 to 10 s−1. Flow stress decline ratio maps as a function of deformation temperature and strain rate were produced along with processing maps at a strain of 0.8 to reveal optimum hot-working conditions for deformation at strain rates of 0.01 s−1 to 0.1 s−1. The results showed that the stress drop ratio during deformation is higher for the homogenized condition than for the pre-rolled, T3 condition. A higher degree of recrystallization after deformation was observed in the pre-rolled, T3 condition due to finer second phase particles, smaller grain size, and more numerous sub-grains. The mechanism for deformation softening is discussed in the context of grain boundary characteristics.
展开▼
机译：研究了7055铝合金在两种热处理条件下（均质化与预轧，固溶处理，拉伸和自然时效（T3））的流动行为和微观结构演变，研究了变形温度为370时高度降低了60％ °C至450°C，应变率范围为0.01 s -1 至10 s -1 。产生了随变形温度和应变速率变化的流变应力下降比图，以及在应变为0.8时的加工图，以揭示变形速率为0.01 s -1 至变形的最佳热加工条件。 0.1 s -1 。结果表明，均质条件下的变形过程中的应力下降率要高于预轧T3条件。在预轧T3条件下，观察到变形后较高的重结晶度，这是由于第二相颗粒更细，晶粒尺寸更小以及子晶粒更多。在晶界特征的背景下讨论了变形软化的机理。
展开▼
